Fall 2005
Harvey Mudd College
Lectures: Monday
and Wednesday, 11am - 12:15pm, Jacobs B132
Instructor: Prof.
Lori Bassman, lori_bassman@hmc.edu, Parsons 2371, x71250
Office Hours: Monday
2:30-5 pm (E190D priority 4:30-5)
Tuesday and
Thursday 2:45-4:00, or drop by.
Textbook: Paul Mitiguy, Dynamics
for Mechanical, Aerospace and Biomechanical Engineers, 2005.
Download Autolev (HMC only) and Autolev installation instructions
MSC Software (Working Model
web site)
Autolev and Working Model are also in the ECF.
Note for when you install Working Model on your own machines: the
license code printed on your CDs is not current. There’s a new one in the syllabus I handed out first class.
Chapter
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Errors |
Typos |
Suggestions for improvement and random comments |
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1 |
1.4.2 Footnote a indicates points on an x axis but the figure shows a function of t |
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2 |
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2.1 Students know well what scalars and vectors are; dyadics are the new thing so include more than one example in the table |
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3 |
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3.4.1 The rotation table relates the a’s to the n’s (either direction). For the rotation matrix it would be clearer to say aRn is the rotation matrix from n’s to a’s, or something to clarify the direction. 3.5 Explain that Autolev results are transposes of what we’d expect (at least if the syntax of the output matches Matlab matrix syntax.) |
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4 |
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Summary “...a computationalLY efficient formula” 4.2 “...there EXIST three...” 4.5 “When v1, v2, v3 are FUNCTIONS...” 4.10 Section title missing “with” 4.10 Comment on line (8) says q, not theta. |
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5 |
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6 |
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6.4.3 Last sentence “This term is...” has a grammar issue. |
6.2.3 I find it a bit confusing that the velocity of BQ in N is defined in terms of the position vector from P to Q instead of from P to BQ. Clearly they are the same vector at the instant, but the way it’s written is inconsistent with golden rule notation. 6.5 This table is incredibly helpful. |
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7 |
7.2 Eq. 1 should have one term with BA and the other AB. |
7.2.3 Final step should say solving these equations for xdot and ωB. |
7.2.3 I found this example confusing on first read, probably because there are so many potential angular velocities and the angular velocity of B in N is one of the more difficult to picture physically. I instead did a more straightforward problem of a ball bearing (ball rolling on the inner and outer wall of a race.) |
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8 |
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8.3–8.6 When teaching this I definitely wanted to do the more accessible topics (linear and angular momentum and kinetic energy) before the inertia dyadic. Switch order? 8.4 Why is more of chapter 10 not here? I’m doing the parts you refer to - 10.7 and 10.8 and the particle example in 10.9.1 and 10.10.1 - at this time. Otherwise equation 1 (in section 8.3) is mysterious. |
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9 |
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10 |
10.5. Values for A2 in the table are wrong. The mass should be 0.5*π, the position vector should be 0.5nx + (1+2*0.5/π)ny, and then the final column changes accordingly (and the final sum). 10.5 The symbols Ai are used both to represent the bodies themselves and the points at their centers of mass. |
10.4 Reference frame N isn’t shown in the figure or defined (not confusing what you mean it to be though...) 10.9.4 Line 1: effects should be affects. 10.10.4 Line 3: Confusion can be exasperating, but probably here it is “exacerbated.” |
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HW1 |
1.6 Crosses missing in distributive property statement 1.12 Last line should say SCALAR triple product 1.17 Footnote 5 gives the commands for (b), not (a) 1.18 Problem asks for cRb but Result table is arranged as bRc |
1.11 Last line in (d) should be v × w 1.13 “Form the unit vector u havING...” |
1.17 The transpose issue is quite confusing. Why is the convention for by-hand work different from the Autolev output? |
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HW2 |
2.14 I was wrong about this one, ignore. [The Result expression should have Ldot in the first term instead of thetadot]. |
2.2 Footnote says “x, y and t” instead of “..and z.” |
2.10 I used the result of problem 2.11 to prove 2.10. Is that what you intend? If so, switch them? |
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HW3 |
3.15 The answer in (d) assumes the angular velocity is constant (but the problem doesn’t say it is). |
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3.6 The simulate task in (d) comes without instruction. Earlier in the book there was an example of how to use Code in Autolev to solve nonlinear algebraic equations, but there’s no prep for Code ODE() (how to specify initial conditions with input, specify output quantities). 3.9 Boy does that get long if you try to do the acceleration by hand. No suggestion here, we just had to get that off our chests. |
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General Autolev |
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- Is there a way to change the working directory? - Is it intentional that quantities that are reported but not assigned [e.g. an Evaluate( ) command versus x = Evaluate( )] don’t show up in .all files? - How can we turn off that beep!?! |